Small/effective in-cab sound damping project for manual trans

[JGK]

For those of you trying to quiet the cab a bit from the engine noise, I may have found a worthwhile project for the 5 and 6 speed trucks.



A few weeks ago I had a new clutch put in. Afterward it seemed like there was a little more noise than before coming from the floor around the hump. I know the plastic cowling around the shifters had to be pulled up to disconnect the stick from the trans. So, thinking something didn't get put back right I popped the boot. Everything looked OK but I thought I'd see if I could improve things.



There's a secondary rubber boot around the base of the main shifter (mine's a 4X4 - 2 shifters) that is screwed to the hump. It looked to be in place. I decided to get creative and used some heat shield insulation to build a second boot around the first one with some cut pieces, a little foam glue and duct tape. I added a patch to the bare metal floor around the 4X4 shifter as well. It helps to unscrew the cowling from the floor and raise it up.



This heat shield stuff is about 3/8 inch thick fiber padding with aluminum foil on one side. I got mine locally but essentially the same stuff can be had out of J. C. Whitney (cat. # 25US0705N, pg. 83 in latest catalog).



Anyway, I put everything back together and fired it up. I'd say it definitely helped. Only took me about an hour and was worth the effort. Did as much good as dynamatting the entire floor one Saturday a few months ago.



Must be a lot of sound that comes up through those 2 boots and/or the mechanic left something out!



A faster and easier alternative might be to just pull the boot up (incl. the 4X4 shifter if you have it) and stuff the cowling with some fiberglass or polyester batting.



-Jay

 

[Roger rodbolt]

Jay,

When replacing a clutch, I just fill the shifter cavity with foam shipping "peanuts". A shop vac will remove them easily if needed. Not sure how effective this is compared to your insulation but it does deaden the noise.

 

[moparguy]

Head hung in shame... ... well, I did the same a couple of years ago as part of a two day, low capital sound damping project. You know interior out, glue rubber sheets to everything, 1/2 rubber to floor and cab back, 1/8th between door glass and door, just the regular effort.



What I found was the more I did, the more I noticed the remaining sounds, and one of the big culprits was the transmission area. Wraped the shifters with a heavy Carhart coat and it got a lot better, very noticeable improvement.



So I then sourced some black naughyde, glued carpet foam to it, stapeled, glued and shaped it around the shifters like a huge shifter boot, and lowered the sound level a few more decibles. The truck was now much quiter without a muffler than it had everbeen in stock form.



Shouda reported sooner.



Ronnie